1. Field of the Invention
The present invention relates to a current sensor having a conductor and two magnetic field sensors adjacent to the conductor.
2. Description of Related Art
Various types of current sensors having Hall elements as magnetic field sensors are known. One type of current sensor having a flux concentrator for intensifying the magnetic field at the location of the magnetic field sensor typically utilizes a single magnetic field sensor which is situated in an air gap of the flux concentrator. The disadvantage of this type of sensor is a large physical size and a high component weight. The physical size prevents, for example, the sensors from being integrated into mold-base power modules. Additional disadvantages are hysteresis effects that occur when the field strength acting on the flux concentrator exceeds a maximum value, for example, due to currents in connection with high interference fields lying outside of the sensor's measuring range. Another type of current sensor has one or a plurality of one-dimensional magnetic field sensors directly adjacent to the conductor. This sensor type is suitable for integration into mold-base modules; however, it is unable to compensate for any interference fields. One version of this type having two magnetic field sensors situated symmetrical to the conductor in a differential configuration is able to eliminate a homogeneous interference field. However, non-homogeneous magnetic fields generate an interference which significantly reduces the achievable accuracy, eliminating this system for applications having exacting measuring accuracy requirements, for example, 2% combined error. Such a sensor is described, for example, in US Patent Application Publication 2006/284613.